The function of the Exposure Core is to provide support in inhalation and other routes of exposures of sulfur mustard, therapeutic agents and other compounds of rodents to well-characterized test atmospheres that are required in the research plans of Project 1-5. The support will include (1) inhalation exposures of animals to SM vapor and aerosol/vapor mixtures, (2) animal dermal exposure to SM vapor, (3) animal ocular exposure to SM vapor, (4) inhalation exposure of therapeutic agents for efficacy, (5) in vitro exposure of tissues and blood to SM vapor, and (6) inhalation exposure to cigarette smoke for animal emphysema model. We have unique facilities and expertise to conduct these animal exposures with different routes of administration including inhalation, dermal, and ocular exposures to SM, inhalation exposures of therapeutical drugs and cigarette smoke, and in vitro exposure of tissues. We will provide services for (1) developing and performing inhalation exposures for animal studies, (2) ensuring high-quality exposure atmospheres (reproducible, stateof- the-art), (3) ensuring that the exposure generation system is operated and maintained according to predefined specifications, and (4) manipulating exposure atmospheres (e.g., adjusting concentration and size distribution of generated aerosols) for meeting the requirements specified for a given study. We have a permission to use and store chemical agents. We also have approved waste management and waste disposal practices for radioactive material. The Exposure Core is essential for the success of the proposed studies in this Center for Countermeasures Aagainst Chemical Threats.